Timeline Cache File Amount - Hitfilm Express

NoIdeaWhatImDoing Posts: 2 Just Starting Out


I just updated to the latest version, and I found my Cache folders beeing flooded with files.

363k files after a single 1h 40min 1080p 60fps video, 22.3 GB size in total.

The HDD was constantly at 100% activity (a WD Raptor with 10000rpm) even after closing the program the HDD was still at 100%.


Best Answer

  • Triem23
    Triem23 Posts: 20,070 Ambassador
    Accepted Answer

    What you describe is the normal and expected behavior in your current configuration of Hitfilm.

    Rather than the old RAM preview writing a temp video file into RAM it's writing individual frame images to the cache.

    A 1-hour, 40 minute, 60 fps video is 360k frames.

    The cache is designed to render the individual frames for quick playback. By writing individual frames, if you make a change at, say 45 minutes in, that section can be recached without altering the existing frames elsewhere.

    Timeline caching is of more value when using multiple tracks, with heavy effects and/or compositing. If you're just trimming a video with minor color correction, you might not need it on.

    In the Hitfilm Manual you should read section 4.7.2, which discusses configuring Cache Options (normally I turn off auto caching and use Manual caching), including setting the default folder, determining if files auto or manually cache, how long to store cached files and manually clearing cached files.

    I can't verify this, but I suspect an assumption is being used by the devs that most storage drives are SSDs. Although you have a rare 10000RPM HDD even 20 years ago that would have been considered barely adequate for 720p footage. For 1080, 60p footage I'm not surprised you're seeing a lot of drive access. The Timeline Cache does fairly constantly output frames while doing its thing. Additionally, while the Raptor is actually a three-platter RAID designed to be a fast Enterprise-use HDD its sustained data rate is only considered about 200Mb/s - which is under half that of the typical 480Mb/s of an entry level SSD (Enterprise level SSDs can sustain 3500Mb/s)